Nikki Johnston, PhD

Nikki Johnston, PhD

Professor, Otolaryngology & Communication Sciences and Microbiology & Immunology


  • Otolaryngology & Communication Sciences

Contact Information


PhD, Molecular and Cellular Pathology, University of Dundee, United Kingdom, 2002
BS, Anatomical Sciences, University of Dundee, United Kingdom, 1999

Honors and Awards

Broyles-Maloney Award American Broncho-Esophagological Association Orlando, Florida - April 2013
Charles Ferguson Clinical Research Prize, American Society of Pediatric Otolaryngology - March 2013
2012 Faculty Service Award for service to the Faculty Council Committees of the MCW - October 2012
Marquis Who’s Who in America 2013 - January 2012
Marquis Who’s Who in Medicine and Healthcare 2012 - June 2011
American Cancer Society / MCW Cancer Center Travel Award, to attend and present at the annual AACR conference, Orlando, Florida - March 2011
Broyles-Maloney Award, American Broncho-Esophagological Association, Phoenix, Arizona - May 2009
Broyles-Maloney Award, American Broncho-Esophagological Association, Orlando, Florida - May 2008
Best Abstract and Travel Award, The Union of European Gastroenterology Week, Copenhagen, Denmark - July 2005
Key Note Presentation, World Organization for Specialized Studies on Disease of the Esophagus, Paris, France - September 2003
Best Abstract and Travel Award, The Union of European Gastroenterology Week, Geneva, Switzerland - October 2002

Research Interests

Nikki Johnston Lab

Research Focus

  • Extraesophageal reflux
  • Use of pepsin as a marker for extraesophageal reflux
  • Uptake of pepsin by laryngeal epithelial cells & its role in reflux - attributed laryngeal injury & disease
  • Isolate and identification of the receptor with which pepsin interacts on laryngeal epithelial cells
  • New therapeutics for reflux (pepsin inhibitors/receptor antagonists)
  • Role of reflux, specifically pepsin, in laryngopharyngeal cancers
  • Role of pepsin in Barrett’s esophagus and esophageal adenocarcinoma

Dr. Johnston’s research laboratory aims to test pepsin, as a marker for reflux, in clinical tissue and secretion samples from patients with diseases of the upper airway, demonstrate the effect of nonacid pepsin on respiratory epithelium using in vitro and in vivo models, and identify the molecular signaling pathways through which nonacid pepsin elicits cell damage. She has been investigating the role of reflux, specifically pepsin, in injury and disease of the aero-digestive tract for several years now. Dr. Johnston has presented this work at national and international scientific and clinical meetings and directed two international conferences on extra-esophageal reflux disease, the future: diagnosis and treatment. She has published the data in several peer reviewed journals, contributed chapters for reflux-related books, and edited a book on this subject.

In addition to investigating the role of pepsin as a diagnostic marker for reflux and its role in the pathophysiology of reflux-attributed inflammatory disease, her group has highlighted a potential role for pepsin in carcinogenesis of the laryngopharynx. Her research team is currently performing experiments to elucidate pepsin as a promoter/causal agent involved in early events of carcinoma in the laryngopharynx, and to investigate the mechanism by which pepsin causes/contributes to inflammation and carcinogenesis in the laryngopharynx.

Society Memberships

  • American Association for Cancer Research
  • Society for Bimolecular Sciences
  • Association for Research in Otolaryngology
  • American Broncho-Esophagological Association
  • Medical College of Wisconsin Cancer Center
  • Clinical and Translational Science Institute of Southeast Wisconsin